Aldous Huxley explores the unfathomed depths of personhood

Human beings are immensely complicated creatures, living simultaneously in a half dozen different worlds. Each individual is unique and, in a number of respects, unlike all the other members of the species. None of our motives is unmixed, none of our actions can be traced back to a single source and, in any group we care to study, behavior patterns that are observably similar may be the result of many constellations of dissimilar causes.

To see ourselves as others see us is a most salutary gift. Hardly less important is the capacity to see others as they see themselves.

We live together, we act on, and react to, one another; but always and in all circumstances we are by ourselves. The martyrs go hand in hand into the arena; they are crucified alone. Embraced, the lovers desperately try to fuse their insulated ecstasies into a single self-transcendence; in vain. By its very nature every embodied spirit is doomed to suffer and enjoy in solitude. Sensations, feelings, insights, fancies — all these are private and, except through symbols and at second hand, incommunicable. We can pool information about experiences, but never the experiences themselves. From family to nation, every human group is a society of island universes.

Most island universes are sufficiently like one another to permit of inferential understanding or even of mutual empathy or “feeling into.” Thus, remembering our own bereavements and humiliations, we can condole with others in analogous circumstances, can put ourselves (always, of course, in a slightly Pickwickian sense) in their places. But in certain cases communication between universes is incomplete or even nonexistent.

The mind is its own place… Words are uttered, but fail to enlighten. The things and events to which the symbols refer belong to mutually exclusive realms of experience.

-from The Doors of Perception by Aldous Huxley (July 26, 1894–November 22, 1963